// Copyright (c) 2017 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef LIBSPIRV_SPIRV_STATS_H_
#define LIBSPIRV_SPIRV_STATS_H_

#include <map>
#include <string>
#include <unordered_map>
#include <vector>

#include "spirv-tools/libspirv.hpp"

namespace libspirv {

struct SpirvStats {
  // Version histogram, version_word -> count.
  std::unordered_map<uint32_t, uint32_t> version_hist;

  // Generator histogram, generator_word -> count.
  std::unordered_map<uint32_t, uint32_t> generator_hist;

  // Capability histogram, SpvCapabilityXXX -> count.
  std::unordered_map<uint32_t, uint32_t> capability_hist;

  // Extension histogram, extension_string -> count.
  std::unordered_map<std::string, uint32_t> extension_hist;

  // Opcode histogram, SpvOpXXX -> count.
  std::unordered_map<uint32_t, uint32_t> opcode_hist;

  // Histogram of words combining opcode and number of operands,
  // opcode | (num_operands << 16) -> count.
  std::unordered_map<uint32_t, uint32_t> opcode_and_num_operands_hist;

  // OpConstant u16 histogram, value -> count.
  std::unordered_map<uint16_t, uint32_t> u16_constant_hist;

  // OpConstant u32 histogram, value -> count.
  std::unordered_map<uint32_t, uint32_t> u32_constant_hist;

  // OpConstant u64 histogram, value -> count.
  std::unordered_map<uint64_t, uint32_t> u64_constant_hist;

  // OpConstant s16 histogram, value -> count.
  std::unordered_map<int16_t, uint32_t> s16_constant_hist;

  // OpConstant s32 histogram, value -> count.
  std::unordered_map<int32_t, uint32_t> s32_constant_hist;

  // OpConstant s64 histogram, value -> count.
  std::unordered_map<int64_t, uint32_t> s64_constant_hist;

  // OpConstant f32 histogram, value -> count.
  std::unordered_map<float, uint32_t> f32_constant_hist;

  // OpConstant f64 histogram, value -> count.
  std::unordered_map<double, uint32_t> f64_constant_hist;

  // Enum histogram, operand type -> operand value -> count.
  std::unordered_map<uint32_t,
      std::unordered_map<uint32_t, uint32_t>> enum_hist;

  // Histogram of all non-id single words.
  // pair<opcode, operand index> -> value -> count.
  // This is a generalization of enum_hist, also includes literal integers and
  // masks.
  std::map<std::pair<uint32_t, uint32_t>,
      std::map<uint32_t, uint32_t>> operand_slot_non_id_words_hist;

  // Historgam of descriptors generated by IdDescriptorCollection.
  // Descriptor -> count.
  std::unordered_map<uint32_t, uint32_t> id_descriptor_hist;

  // Debut labels for id descriptors, descriptor -> label.
  std::unordered_map<uint32_t, std::string> id_descriptor_labels;

  // Historgam of descriptors generated by IdDescriptorCollection for every
  // operand slot. pair<opcode, operand index> -> descriptor -> count.
  std::map<std::pair<uint32_t, uint32_t>,
      std::map<uint32_t, uint32_t>> operand_slot_id_descriptor_hist;

  // Histogram of literal strings, sharded by opcodes, opcode -> string -> count.
  // This is suboptimal if an opcode has multiple literal string operands,
  // as it wouldn't differentiate between operands.
  std::unordered_map<uint32_t, std::unordered_map<std::string, uint32_t>>
      literal_strings_hist;

  // Markov chain histograms:
  // opcode -> next(opcode | (num_operands << 16)) -> count.
  // See also opcode_and_num_operands_hist, which collects global statistics.
  std::unordered_map<uint32_t, std::unordered_map<uint32_t, uint32_t>>
      opcode_and_num_operands_markov_hist;

  // Used to collect statistics on opcodes triggering other opcodes.
  // Container scheme: gap between instructions -> cue opcode -> later opcode
  // -> count.
  // For example opcode_markov_hist[2][OpFMul][OpFAdd] corresponds to
  // the number of times an OpMul appears, followed by 2 other instructions,
  // followed by OpFAdd.
  // opcode_markov_hist[0][OpFMul][OpFAdd] corresponds to how many times
  // OpFMul appears, directly followed by OpFAdd.
  // The size of the outer std::vector also serves as an input parameter,
  // determining how many steps will be collected.
  // I.e. do opcode_markov_hist.resize(1) to collect data for one step only.
  std::vector<std::unordered_map<uint32_t,
      std::unordered_map<uint32_t, uint32_t>>> opcode_markov_hist;
};

// Aggregates existing |stats| with new stats extracted from |binary|.
spv_result_t AggregateStats(
    const spv_context_t& context, const uint32_t* words, const size_t num_words,
    spv_diagnostic* pDiagnostic, SpirvStats* stats);

}  // namespace libspirv

#endif  // LIBSPIRV_SPIRV_STATS_H_